- What
is an MX record?
- Is
an MX record the same as the server I download my mail from?
- What
is the proper format for an MX record?
- Why
is the proper format so important?
- Will
Yahoo! Domains add MX records for me that are not properly
formatted?
What is
an MX record?
When a remote site on the internet wants to send someone at your
domain an email message, itws mail server software uses the global
DNS system to look up the hostname of the appropriate mail server
to receive that mail. This type of record is referred to as an
"MX," "Mail Exchanger" or "Mail
Relay" record. The response that the remote server gets tells
it where to send the mail so that it will be relayed to you.
Is an
MX record the same as the server I download my mail from?
When your site has received email, it is stored for you by your
email server. In order to retrieve your mail from the server, you
need to use an interface between your mail program (like Eudora
or Netscape) and the mail
server itself. This interface is usually a piece of software like
POP (the Post Office Protocol) or IMAP. The
hostname that you use to access the POP or IMAP server might be
the same as your MX record, or it might be different. The MX
record's only job is to tell other sites where mail for you should
be sent. You retrieving your mail is a completely separate
operation from the standpoint of the DNS.
What
is the proper format for an MX record?
Here's an example of an MX record:
MX 10
mail.domain.com
The above example
specifies that the host with the name mail.domain.com is
designated to receive all the email addressed to this domain.
You can also set up
multiple MX records, as in the following:
- MX 10 mail.domain.com
- MX 20
mail2.domain.com
- MX 20
mail3.domain.com
If you have multiple
email servers set up to handle your email, you can set up multiple
MX records for a reliability and redundancy. If the primary mail
server is down, the mail message will be temporarily sent to
another mail server designated by the MX record. In the above
example, if the primary mail server mail.domain.com does not
respond, a delivery will be attempted to the host
mail2.domain.com. If that host is also down, then another attempt
to the host mail3.domain.com will be made. The number associated
with each MX record specifies the priority of the mail servers.
The lower the number, the higher the priority.
Why
is the proper format so important?
Without the proper format, the chances of your mail being
delivered properly go down. As the abuse prevention systems that
check for proper format become more and more common, your chances
for having the mail delivered properly go down even more. If you
have improperly formatted MX records and remote sites are not able
to send you mail, chances are you will never know.
There are many sites that simply discard undeliverable mail and
never attempt to find an alternate contact address to let you know
that your email is not being delivered.
Will
Yahoo! Domains add MX records for me that are not properly
formatted?
Our goal at Laguna Beach Internet is to provide our customers with the
best service possible. Therefore, if you ask us to add records
that violate internet standards, we will do everything we can to
work with you so that when we add your custom DNS records they
will actually accomplish what you want to happen. However, we will
add records for you that we know are not 100% effective, as long
as they do not cause errors on our nameservers.
